Radio system performance and architectures are highly dependent on filter technologies. In a superheterodyne radio, for example, high levels of selectivity are created through the use of one or more Intermediate Frequency (IF) sections with decreasing bandwidths that are largely dictated by the filter technologies available. LC circuit filters, bulk acoustic wave filters, or ceramic filters may be utilized at higher frequencies in a radio while surface acoustic wave or crystal filters may be used to provide the final analog bandwidth for that radio.
One of the measurements used for filter selectivity is the loaded Q (quality) factor, defined as the filter's center frequency divided by its bandwidth. It is noted that current technologies used to construct the various filters mentioned above have limited loaded Q factors, which may limit the dynamic range of such filters. Additionally, since the final analog selectivity is not obtained until the final IF, circuits handling the signals prior to the final analog selectivity must accommodate the desired signal as well as all interfering signals. Since interfering signals falling within the widest front end filters will be amplified along with the desired signals, the dynamic range requirements of the front end circuits are further increased.